1. Field of the Invention
The present invention relates to a developer removal method and a developer removal device for removing developer remaining inside a used developing device in order to reuse the developing device.
2. Related Art
Conventionally, a developing unit filled with toner is installed in a freely insertable and removable manner in an electrophotographic image forming device, such as a laser printer.
This kind of developing unit is divided into a toner chamber and a developing chamber. The toner chamber is filled with toner and provided with an agitator. The developing chamber is provided with a supply roller, a developing roller disposed in opposition to the supply roller, and a thickness regulation blade pressed against the surface of the developing roller.
When motive power from the laser printer is input to the developing unit by a gear train or the like, toner in the toner chamber is transported to the developing chamber by rotation of the agitator. The toner transported into the developing chamber is then supplied to the developing roller by rotation of the supply roller. At this time, the toner is triboelectrically charged between the supply roller and the developing roller. Also, as the developing roller rotates, toner supplied to the surface of the developing roller comes between the thickness regulation blade and the developing roller, and is held on the surface of the developing roller as a thin layer of uniform thickness.
The developing unit is installed into the laser printer such that the developing roller is located in confrontation with a photosensitive drum. When toner held as a thin layer on the surface of the developing roller comes into opposition to the photosensitive drum, the toner forms a toner image by developing an electrostatic latent image formed on the surface of the photosensitive drum. Thereafter, the toner image is transferred onto a paper sheet by a transfer roller.
The toner in the toner chamber is consumed in this manner. When no toner is left, the laser printer gives an “out of toner” indication prompting the user to replace the developing unit. The user therefore removes the used developing unit and installs a new developing unit.
In recent years, however, from a recycling standpoint, it has become common for used developing units not to be discarded but to be refilled with toner and reused.
When refilling a used developing unit with new toner, it is necessary to remove toner remaining inside the used developing unit to such an extent that the residual toner does not affect the insertion and use of the new toner.
Japanese Patent Application-Publication No. HEI-7-84444 proposes a method of removing such residual toner. In this method, a developing unit is supported with its developing sleeve facing upward by a movable supporting stand placed in a standby position. Then, the supporting stand is moved to an operational position, and a sleeve gear of the developing sleeve is engaged with a drive gear. A suction aperture at the end of a suction nozzle is inserted in a toner chamber, and the residual toner in the toner chamber is sucked up by the suction nozzle while the developing sleeve is driven to rotate by a motor.